Swap Fedora 17 & 18 for 20.  Recognize the SWAMP platform strings so that they build correctly.
Merge branch 'V8_1_6-branch' of ssh://ingwe.cs.wisc.edu/p/condor/repository/CONDOR_SRC into V8_1_6-branch
Merge remote-tracking branch 'origin/V8_1_6-branch'